String won't stop advancing and tangles around the unit

when you are holding the spool on which you wind the string wind the string on in a anticlockwise direction
if it uses 2 strings ( one out of each side of the spool
wind in both strings together in the anticlockwise direction
that way , when you put the spool in the head and go to use it , the string is wound the right way to feed out and not get tangled

Ensure you are winding the line in the correct direction

I had the same issue, my son used his all of half a day and the elevator stopped working. If you take the top of the cave off, and unscrew it from the elevator shaft you will see a black wheel. The string needs to be wrapped around this twice, there should be very little play in the string. What I had to do was take out the 3 screws that held it to the knob on top, then wrap the string back around the wheel making sure not to tangle the string more. once the string is wrapped 2 times you can reassemble.

Hello, W/D here.
It should pull straight off. It may take a bit of force, and tapping on the bulbous head of the spool (the part that you bump on the ground to advance the line) will help to free it up.
Here's a link to how the spool works, and how to re-wind it:
http://www.fixya.com/support/r2827867-winding_line_trimmers
Best regards, --W/D--

You do not need to bump the head to advance the line. The machine has automatic line feed. If the line will not advance, then there is a problem with the line spool, possibly a tangle inside on it. Here is your instruction manual.
http://tinyurl.com/2vz3fhb

These little electric machines have an automatic line feeding system. Do not bump the trimmer head on the ground attempting to make line advance. If the line advance is not functioning like it should, then the string head should be removed and the spool inspected for snags and tangles.

You need to start from the beginning of the trimmer string. Remove the entire spool. Insert the start of the line through and wedge it into the little groove to keep it from coming loose. Now wind the line tightly and neatly in the direction shown on the spool. (it should provide an arrow stating to "wind this way". As you near the end of the line, keep it snug and push the end through the hole where it leads out to the cutting zone. As you re-insert the spool into the housing, make sure it stays tightly wound as you lock it into place. This should help. Usually when your string is too short, you tap the **** (bottom) of the spool on the ground to advance the line. It should feed a bit at a time, and when you hear it getting cut off, you should stop advancing the line.
Hope this helps.

Go to home depot. look at the floor model and the replacement spools they sell there. Reverse engineer the stringing process or but a pre-loaded spool.
Otherwise,
1. Squeeze the tabs on the side of the head of the unit to remove the spool cover.
2. remove spool.
3. place end of string in small hole in center ring of spool.
4. wide spool with string in the direction of the arrows printed on the spool. DO NOT OVERLOAD!.
5. snap string into notch on spool and cut string leaving 6" exposed.
6. thread 6" of string through hole in side of unit head, replace spool, and replace cover.
7. go cut grass.

Cut two separate pieces of string, about 7 ft. each.

Stick the end of the line in the hole on the inside of spool.

Wind clockwise onto spool, putting the line that is closest to the ground on first.

Once you have winded this piece on, lock the last 4 inches of line through the slits on spool.

Repeat process for second piece of line, locking the last 4 inches in slot opposite the other locked in piece.

Put the spool on the trimmer, feeding the end of lines through either hole on trimmer.

Before you push the spool all the way on, pull the strings out of the locked position.

Jim

Sounds as if the line is wound on the spool the wrong way, causing it to want to always feed string.

Jim